I bought this pattern book, there'ss a beautiful baptism/christening dress in there that I want to make. I have some parts of the pattern that totally be-fuddle me. Has anyone used this book, or got the book, so I could ask you my specific question. It mentions an over-lay and an under-lay made from stitches picked up on the neckline. This may be terms used in England that aren't familiar here. What do those 2 terms mean?